Tool cartridge having an elastic matrix

ABSTRACT

A press for massive forming has a tool frame used for closing matrixes which form mold halves for a forming operation which takes place in the closed mold. The closing devices contain driving devices and, together with these, are housed in or on the cartridge. They are formed by a spring device, in which the closing force is applied by the closing device (spring, pneumatic spring, ring piston with nitrogen reservoir). The closing movement is carried out by the slide movement.

BACKGROUND OF THE INVENTION

[0001] This application claims the priority of 199 62 607.3, filed Dec. 23, 1999, the disclosure of which is expressly incorporated by reference herein.

[0002] The present invention relates to a tool cartridge which is provided particularly for a press for massive forming.

[0003] Presses provided for massive forming are machines which can be tooled by special tools within their capacity for producing different workpieces. During massive forming, the workpieces, as a rule, travel successively through several tools, in which case, starting from a blank, they are progressively formed in steps until they have the desired shape. For this purpose, the press, as a rule, has only a bedplate and a slide, whereby the tools divided into a top tool and a bottom tool are each jointly connected with the bedplate and the slide. Generally speaking, the tools are held for this purpose in so-called tool cartridges.

[0004] For critical forming tasks, tools are in use which have movably disposed tool parts. For example, one movably disposed matrix respectively can be provided in the top tool and the bottom tool. The matrixes each form a mold half of a mold which is closed as early as before the lower dead center of the press slide and in which the forming is carried out by punches fixedly connected with the slide. During this forming operation, the mold must be tightly closed; that is, the mold halves must be pressed together. The mold halves cannot be firmly connected, however, with the slide and/or the bedplate because the mold closes already before the lower dead center of the slide is reached.

[0005] In order to apply the force required for holding together the mold halves, corresponding measures must be taken as a rule in the bedplate or the slide. The corresponding tool mounting site has to be especially prepared for this purpose. This limits, however, the versatile usability of the press. If, in contrast, corresponding force generating devices are to be arranged, for example, in an intermediate plate, which is arranged in each case between the bedplate and the bottom tool or the slide and the top tool, a considerable installation space is required.

[0006] If the intermediate plate is used as well as in the case of presses with installed force generating devices (also called closing devices), it has to be defined in which stations, that is, tool positions, the force generating devices are required. It is neither expedient nor desirable to provide force generating devices in every position in a preventative manner. In addition to the constructive expenditures connected therewith, the usage possibilities of the press are also limited thereby.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide movable tool parts on a versatile press, which tool parts, can be acted upon in a simple manner by a required holding force.

[0008] According to the present invention, a tool cartridge is provided for receiving the tools. The cartridge can accommodate tool by way of movable matrixes and which contains at least one force generating device, i.e., a closing device, for the corresponding matrix. The tool frame has several tool bearing devices in the cartridge, on which tool bearing devices in each case individual tools, which correspond to the respective forming stations, are to be arranged in a stationary or movable manner. At least one of the forming stations requires a movably disposed tool part which is called a matrix. For the movable bearing of this tool part, a guide is provided on the tool bearing device. Correspondingly, the tool cartridge can be provided with one or several guides.

[0009] In order to be able to prestress the matrix in a moving direction which is opposite to the working direction of the press, an uncontrolled or controlled force generating device (spring device) is arranged in the tool cartridge. The force generating device is arranged completely in or on the frame on the tool cartridge. As a result, all devices required on a corresponding forming station for applying the closing force of the matrixes are housed in or on the tool cartridge and thus also in or on the tool frame. The corresponding area of the slide or of the bedplate requires no separate preparation. Only a frame is required in which cartridges with or without closing devices can be installed. The closing devices can be installed in every station in which they are required. Separate constructions are required neither at the slide nor on the receiving plate. This increases the flexibility of the press and reduces the costs during its manufacturing. Possibly existing intermediate plates between the tool cartridge and the bedplate require no significant installation space because they can be thinner than the required matrix stroke. This does not reduce the existing installation height of a press which defines the tool installation space. In addition, the intermediate plate can be set up non-specifically for receiving different cartridges.

[0010] The cartridges are preferably fixed by way of conical receiving devices in the base plate and/or head plate of the tool frame. They are therefore easily exchangeable and can be tensioned manually or hydraulically.

[0011] The matrix is supported by the force generating device on the tool frame, i.e., on the cartridge or on the base plate. In a further development of the present invention, the force generating device can also be combined with the tool bearing device to form one device. The prestressing device, which defines the springing direction, like the moving direction of the tool bearing device, is also aligned parallel to the moving direction of the slide. For the tool cartridge assigned to the bottom tools, the prestressing direction is opposite to the working direction of the slide, while, in the case of the slide-side cartridge, it coincides with the working direction of the slide.

[0012] The force generating or closing device, tensions the matrix in a defined manner against a stop, so that the tool can open as soon as the force generating device has arrived at its stop. The stroke defined by the force generating device, the guiding device and the stop is therefore smaller than the press stroke.

[0013] The force generating device can generate an essentially constant force. This can be carried out particularly by a pneumatic force generating device (pneumatic spring device) which is formed by one or several pistons which, by way of a pressure accumulator, are acted by compressed air or by a pressurized hydraulic fluid. In this case, the pressure accumulator is carried by the tool cartridge. The tool cartridge can be exchanged without having to interrupt pressure lines, empty pressure vessels or take other high-expenditure measures. If the volume change is low, which exists during the movement of the matrix in the pneumatic system, the force generating device generates an almost constant force. If larger volume changes are generated, an approximately linearly rising characteristic force-path curve can be obtained. In addition, a progressive characteristic spring curve can be generated. This applies correspondingly also to mechanical springs, such as coil springs, cup springs or several other relatively strong pressure springs.

[0014] As required, pneumatic spring devices can be provided with an adjusting device for influencing the generated force. In the simplest case, such an adjusting device is a fill-up or discharge valve, such that the pressure can be changed in the pressure accumulator pertaining to the spring device. This permits the adaptation to different circumstances.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

[0016]FIG. 1 is a schematic perspective view of a press for massive forming which is equipped with a multi-station tool frame in a cartridge construction;

[0017]FIG. 2 is a cross-sectional view of the tool frame and the tool cartridge of the press according to FIG. 1, before the closing of the tools;

[0018]FIG. 3 is a cross-sectional view of the tool frame and of the tool cartridge according to FIG. 2, with a closed workpiece;

[0019]FIG. 4 is a cross-sectional view of the tool frame and of the tool cartridge according to FIGS. 2 and 3, after the forming operation; and

[0020]FIG. 5 is a schematic cross-sectional view of a modified embodiment of the tool frame and of the tool cartridge with an open tool.

DETAILED DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a schematic illustration of a press 1 provided for massive forming. The press has a press frame 2 on which or in which a slide 3 is displaceable back and forth in a direction indicated by an arrow 4. A bedplate 5 is provided opposite the slide, which bedplate 5 has a mounting surface for receiving a lower tool part 7. The slide 3 has a corresponding mounting surface 8 which is situated opposite the mounting surface 6. The mounting surface 8 is used for receiving an upper tool part 9. Tool parts 7, 9 together form a tool 11.

[0022] The tool 11 is a multi-station tool which, in the present embodiment, has five tool stations 11 a, 11 b, 11 c, 11 d, 11 e. During a forming operation, each tool station 11 a to 11 e carries out a forming on a workpiece which successively travels through the tool stations 11 a to 11 e. Because all tool stations 11 a to 11 e are arranged on the same slide 3 and on the same bedplate 6, they operate synchronously. For advancing the workpieces from one tool station to the next, a transfer device is used which is not shown in detail.

[0023] The tool 11 may contain one or several forming stations, in which the workpiece is formed in a closed mold, into which the actual forming tools penetrate when the mold is closed in order to displace the workpiece material. Such a tool station is illustrated in FIG. 2. The upper tool part 9 and the lower tool part 7 of the tool 11 each have a tool frame 14, which essentially have an identical construction. The following description of the lower tool part 7 therefore applies correspondingly to the upper tool part 9. Correspondingly identical reference numbers are used in the figures.

[0024] The tool frame 14 includes a tool cartridge 14 a and a base plate 14 b which is mounted on the mounting surface 6 and/or 8. The tool cartridge 14 a has tool bearing devices 15 on which guides 16 for matrixes 17 are arranged. The guide 16 is formed, for example, by the wall of a cylinder opening, in which the matrix 17 is displaceable in a direction coinciding with the working direction (double-headed arrow 4) of the slide 3. On the side away from each of the mounting surface 6, 8, the corresponding opening has an inward-projecting ring shoulder 18 which is used as a stop device for the matrix 17. On the matrix 17, which otherwise has, for example, a cylindrical outer-circumference surface 19, a radially outward-projecting flange 21 is provided so as to come to rest on the ring shoulder 18 and prevent the matrix 17 from moving out of the tool frame 14, i.e., out of the tool cartridge 14 a. In some cases, the tool cartridges 14 a may also be constructed differently, for example, when only one matrix is to be movable and the opposite one is to be fixed.

[0025] The matrix 17 forms a mold half or a die whose die sinking 22 defines the external shape of a workpiece to be formed. For this purpose, the matrix 17 may have a corresponding insert 23. The matrix 17 of the upper tool part 9 and the matrix 17 of the lower tool part 7 have such a contour on their mutually facing sides that, as illustrated in FIG. 3, they fit into one another, the two inserts 23 then enclosing a hollow space 24. The hollow space 24 is closed at a mold parting line 25, at which the corresponding inserts are firmly pressed against one another by their preferably plane faces.

[0026] The spring devices 26, which are housed at least largely in or on the tool cartridge 14 a, are used for pressing the matrixes 17 against one another during the last section of the downward movement of the slide 3, i.e., as the closing device. As illustrated in FIGS. 2, 3 and 4, the spring devices 26 may be one or several pressure springs, such as coil springs, whose longitudinal axis coincides with the moving direction of the matrix 17. Several of these coil springs are arranged on a circle concentric with respect to the matrix 17. The coil springs 27 forming the spring devices 26 will then prestress the matrix 17 to its position pushed the farthest out of the tool cartridge 14 a, so that the flange 21 rests against the ring shoulder 18.

[0027] The insert 23 has an opening 28 through which a punch 29 can enter the interior 24 enclosed by the matrixes 17. The punch 29 is stationarily arranged in the tool cartridge 14 a and forms a forming tool. Its length is dimensioned such that it will not project into the interior 24 when the matrix 17 rests by its flange 21 against the ring shoulder 18. The punch 29 may be exchangeably disposed in the tool cartridge 14 a. For its holding and bearing, a plate 31 can be housed in the tool cartridge 14 a.

[0028] An ejector sleeve 32 is displaceably disposed on the punch 29 and is concentric to the latter. In the inoperative position, i.e., when the matrix 17 is in its most advanced position, the ejector sleeve 32 also does not project into the interior 24. The ejector sleeve 32 can be operated by one or several pressure pins 33 which are applied to the interior ring-shaped face of the ejector sleeve 32. The pressure pin 33 penetrates through the tool cartridge 14 a and is in contact via its other end with a corresponding operating punch 34. Such an operating punch 34 is housed in the bedplate 5 as well as in the slide 3.

[0029] In operation of the tool 11, a workpiece blank is inserted into the open tool (see FIG. 2), while the slide 3 moves downward. The matrixes 17 are first placed upon one another, as illustrated in FIG. 3. The workpiece 40 placed here into the matrix had already been preformed from a blank in preceding forming operations and has a lateral extension 41 which fits into a corresponding lateral extension of the interior 24. During the further downward movement of the slide 3, the matrixes 17 can no longer carry out a relative movement and rest on one another at the mold parting line 25.

[0030] The spring device 26 now increasingly presses the matrixes 17 on one another, while the slide 3 continues to move farther in the direction of its lower dead center. The flanges 21 of the matrixes 17 therefore lift off the ring shoulders 18. Furthermore, the punches 29 (cup punches) advance into the interior 24 and further form the workpiece 40. An ascending edge 42 of this workpiece 40 comes to rest against the ring-shaped face of the ejector sleeve 32 which also forms a portion of the boundary of the interior 27. After the lower dead center has been passed, the end of the forming operation has been reached. The slide 3 now moves away from the bedplate 5, whereby the punch 29 is first moved out of the interior 24 and the matrixes open as soon as their flanges 21 have come to rest on the ring shoulders 18. Part 40 can be removed and be fed to the next forming station.

[0031] In a modified embodiment, which is illustrated in FIG. 5, the spring device 26 is formed by one or several pressure cylinders, whose pistons 45 are disposed in corresponding cylinder bores 46 of the plate 31. In the illustrated embodiment, the piston 45 is a ring piston which is housed in a ring-shaped cylinder space. Deviating therefrom, several pistons 45 may also be displaceably disposed in mutually parallel cylinder bores. The pistons 45 are supported by their faces on the interior pressure surface of the matrix 17. The other face of the pistons 45 partition off one working space 47 respectively in the cylinder bores 46 or in a cylinder liner 46 a, and the working space 47 is acted upon by a pressurized fluid. (In a variation of the ring piston, a ring-shaped working space 47 is formed) . The fluid, preferably hydraulic oil, air or nitrogen, is connected with a pressure accumulator 48 which is carried by a tool cartridge 14 a or is integrated in it. The pressure accumulator 48 is connected with the working spaces 47 by corresponding ducts 49.

[0032] In order to achieve an adjustment of the force acting upon the matrix 17, the ducts 49 can be connected with a valve device 51. The valve device 51 can contain a fill-up valve or a discharge valve. The valve device 51 is, however, preferably not permanently connected with pressure lines or other control elements. As a result, also in this embodiment, as in the above-mentioned embodiment, a tool change can be carried out by exchanging the tool cartridges 14 or also the tool frames 14. Closing devices for the matrixes 17 or only connecting possibilities for the closing devices are to be provided neither on the bedplate 5 nor on the slide 3. The closing device, which is formed by the spring device 26, is part of the tool cartridge 14 a and is therefore independent of the press 1. The tool cartridge 14 a can be installed in presses 1 which have no closing devices and are also not set up for the installation of such a closing device. Because of this concept, the presses can be used in a more versatile manner and can be produced more cost-effectively.

[0033] The cartridge 14 is connected with the tool frame 14 by a conical receiving device 55 which can be fixed by way of screws, hydraulic tensioning devices or other tensioning devices. The cartridges 14 can therefore easily be exchanged.

[0034] For a press 1 for massive forming, a tool frame 14 is provided with closing devices which are used for the closing of matrixes 17 which form mold halves for a forming operation which takes place in the closed mold. The closing devices contain driving devices and, together therewith, are housed in or on the tool cartridge 14 a. They are formed by a spring device 26, in which the closing force is applied by the closing device (spring, pneumatic spring, ring piston with nitrogen reservoir). The closing movement is carried out by the slide movement.

[0035] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

1. Tool cartridge, for a massive forming press for massive forming, which tool cartridge is set up for connection with a tool frame, arranged in the press, and has a plurality of tool receiving devices operatively assigned to tools for successive forming stations, comprising: matrixes configured to be insertable in the tool receiving devices or are inserted thereon and which each is part of a tool; at least one guide for the movable bearing of the matrix, wherein the at least one guide is arranged in or on the tool cartridge and is operatively associated with to the tool receiving device, at which the matrix is to be movably disposed; at least one punch operatively associated with the at least one movably disposed matrix and which is stationarily disposed in the tool frame, and at least one closing device assigned to the tool cartridge and to the movably disposed matrix and which is arranged completely in or on the tool cartridge.
 2. Tool cartridge according to claim 1 , wherein the closing device is a spring device.
 3. Tool cartridge according to claim 1 , wherein the guide has a guiding direction which coincides with a working direction defined by the press, and the matrix is prestressed by the closing device against the working direction of the press.
 4. Tool cartridge according to claim 3 , wherein the spring device is enclosed by the tool cartridge.
 5. Tool cartridge according to claim 2 , wherein the spring device is a pneumatic or hydraulic spring device.
 6. Tool cartridge according to claim 2 , wherein the spring device has at least one mechanical spring element.
 7. Tool cartridge according to claim 1 , wherein ejector devices are associated with at least the tool receiving devices on which matrixes are arranged and are movably disposable.
 8. Tool cartridge according to claim 1 , wherein the closing device is comprising an adjusting device for adjusting a closing force or a characteristic force-path curve.
 9. Tool cartridge according to claim 1 , wherein a conical receiving device operatively connects the tool cartridge with the tool frame.
 10. Tool cartridge according to claim 9 , wherein the conical receiving device includes mechanically or manually operated tensioning devices. 